"Magnetars: Nature's Strongest Magnetic Fields"
Recent observations of two kinds of sources, soft gamma-ray
repeaters
and anomalous X-ray pulsars, have provided compelling
evidence for
the existence of neutron stars with magnetic fields 10-100
times higher
than the quantum critical field. The detection
of long periods and high
spin-down rates in these sources strongly suggest that
they belong to a
new class of star, a "magnetar", which was actually predicted
by theorists
several years earlier. Magnetars are the first
known sources to be powered
by their magnetic energy, which distinguishes them from
the many radio
pulsars that are neutron stars powered by their rotational
energy.
I will review the history of magnetars, discuss the observational
evidence that they really exist and the exotic and fascinating
physics that
operates in these sources.